Blasting apparatus



Oct. 1, 1935. F. w. CAMP 2,016,250

BLASTING APPARATUS Filed Feb, 28, 19:53

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INVENTOR, FRANK W. CAMP Patented Oct. 1, 1935 UNITED STATES.

BLASTING APPARATUS Frank W. Camp, San Francisco, Calii., assignor, bydirect and mesne assignments, of fifteen per cent to Joseph Liberman,San Francisco, Calif., and ten per cent to Bernard B. Stlmmel-Application February 28, 1933, Serial No. 658,928

'1 Claims.

This invention relates to blasting apparatus of the type shown in myprior Patent No. 1,560,038 of November 3, 1925, and has for its objectsimprovements over said apparatus whereby the op erations of blasting maybe more expeditiously carried out. Specific advantages and details, ofconstruction will appear in the following specification and accompanyingdrawing.

Briefly described, the invention consists of a special arrangement offalling weight with a cylindrical rock-penetrating explosive bombattached at the end of the weight, so as to be driven into the rockyformation upon dropping the weight for blasting a passage for subsequentdriving of piles in such formation, the weight being removed before theexplosion takes place.

The principal feature of the present invention consists in the specialmeans of attaching the rock-penetrating bomb to the weight, and theautomatic means for igniting the charge.

Another feature is the provision for use of different diameter bombs.

In the drawing Fig. 1 is an elevation of the suspended weight withoutthe bomb attached but with a rock-penetrating point in place for makinga preliminary entering hole.

Fig. 2 is an elevation of the lower portion of the weight showing thecylindrical pointed bomb in place.

Fig. 3 is a cross section of Fig. 1 as seen from the line 3-4 thereof.

Fig. 4 is an enlarged vertical section of the lower end of the weight ofFig. 1 showing the means of attaching its rock-penetrating point.

Fig. 5 is a cross section of Fig. 4 as seen from the line 55 of Fig. 4.

Fig. 6 is a perspective view of a bushing for the lower end of theweight to adapt it for smaller size cylindrical bombs.

Fig. '7 is an enlarged vertical section of the cylindrical bomb securedby a wedge to the lower end of the weight, and showing the firing pinarrangement.

Fig. 8 is an enlarged view of the lower end of the firing pin shown inFig. 7.

Fig. 9 is a view of Fig. 8 at right angles to the view shown in Fig. 8.

Fig. 10 is an enlarged view of the cap retaining slot for the fuse shownin Fig. 7.

Fig. 11 is an enlarged view of the cap shown in Fig. '7.

In further detail, the weight I is an elongated steel shaft of adiameter and length depending on the size holes to be drilled andblasted (one now in use being about 8 inches indiameter, about 25 feetlong, and weighing about 6000 pounds), and suspended at its upper end bya loop of steel rope 2 or other suitable connection to a swivel joint 3in turn suspended from a cable 4 which passes upward over a supportingsheave, not 5 shown, and to a winding drum, not shown, all in a mannerso that the weight can be raised and dropped like a pile drived weight.

The lower portion of the weight is tapered as shown at I and the sidesare longitudinally 1 grooved as at 5 to let water escape upward when theweight is dropped into rocky formation at the bottom of waterways,- suchas bays, rivers, etc., in making holes for subsequent pile driving.

At the lower end of the weight is a circular recess 6 into which fitsthe stem I of a hard steel rock penetrating point 8, the stem being heldin place by a wedges driven transversely through suitable aperturesformed in the weight and stem of the point.

In Fig. 4 it will beseen that at one side of the recess 6 is a verticalkeyway I0 which joins a circular groove II at its upper end. This is toreceive a pin I2 01 a bushing l3 (Fig. 6) which may be pushed into therecess and turned to bring 25 the pin l2 into the 'groove, II to hold itin place and thus effectively change the bore of the weight to'a smallersize for small diameter bombs.

In Fig. 7 a rock-penetrating bomb is shown in place in the weight (thepreliminary rock pene- 3o trating point 8 having been removed). The bombconsists of a strong cylindrical shell l4 (generally about three feetlong) fitted with a hard steel point I5 at its lower end, and whichpoint may conveniently be sulphured in place with melted sulphur at Itand further welded as at ll around the lower edge of the cylinder l4 anda shoulder formed on the point as indicated. Extending along one side ofthe space within the cylinder is a pipe l8 to hold air and gases for 40proper operation of the 'fuse I9 which extends downward through a massof explosive 20 to a suitable detonator 2| which in turn fires anexploder cap 22. The upper end of the fuse passes through a horizontallyextending pipe nipple 23 3 into pipe I8 where the fuse end is coveredwith a friction ignition substance 24, while slidably positioned abovethe fuse end in pipe I8 is a rod or firing pin 25 carrying at its lowerend a flat spring 26 surfaced with friction material 26' on 50 one facesuch as a sanded surface or otherwise roughened exterior as is-foundon'safety match boxes for striking, so arranged that upon descent theroughened surface will rub across the friction ignition button 24 at theend of the fuse and 5 tory.

ignite the fuse. The firing pin is normally held in raised position bymeans of a stuffing box 21 fitted in the closed upper end of pipe l8 andthrough which the pin passes, and it is pushed downwardly by the descentof the weight I itself upon the point of the bomb striking the earth.The upper end of the firing pin is grooved as at 25' to indicate theproper position of the spring 26 for engaging the button 24. The upperend of the explosive-containing cylinder I4 is sealed over at 28, 28 asby layers of cement followed by a layer of parafilne 30 poured on afterthe upper layer of cement has set, while forced snugly over the end ofthe cylinder isan outer inverted sheet metal cylindrical hood 3|additionally held in place as by a soft metal shearing ring, such aslead, 32, which may be soldered to the inside of outer sheet metalcylinder 3| and rests firmly upon the upper end of cylinder I4 so as tohold the parts in the relation shown with the upper closed end 33 of thehood spaced slightly above the firing pin 25. The bomb assemblage isthen held in place within the recess of the weight by means of one ormore wooden wedges as at 34 pushed upward into the crescent spacebetween the wall of the recess and the outer surface of the hood asshown in Fig. 7. Hood 3| is perforated; at the side as at 35 to permitthe contained air to get out when telescoped by the weight upon the bombreaching the ground.

The diameter of the bombs may be of any size up to the recess in theweight and the wedge can be inserted in the keyway [0, though if verysmall bombs, say of 2 inches or so in diameter, are used, the bushing I3is first placed within the recess so as to better centralize the bomb.

The particular explosive usedfor filling the bombs will depend on thenature of the work being done, but for blasting pile holes in rockyformation I find nitro-starch 60% to be satisfac- In using theinvention, the weight with point attached is generally first droppedabout 50 feet from a pile driving rig into the formation to start thepenetration, then hauled up, the point 8 removed, bomb inserted in itsplace and again dropped. When the point of the bomb strikes the rockhood 3| will be telescoped over cylinder ll, firing pin forced down,fuse ignited, and bomb driven several feet into the rock where it willstick by friction as the weight is at once pulled upward and out of thewater covering the buried bomb before the bomb goes off. The length offuse is is arranged to give about four seconds time for removing theweight although it is obvious that the fuse can be made to give a longeror shorter time as may be desired.

On account of the great weight of theweight I, it will drop like aplummet, and if the blasting is being done through a. great depth ofwater, it will nevertheless strike the same spot any number of timesafter a bomb has been placed in it and again dropped. In fact, a highwind or cross currents in the water have no perceptible efiect on it.

In forming holes of considerable depth, the operations described may berepeated as often as required as the loose rock seems to burn and toblow out of the hole formed or is spread and what remains is easilypenetrated by the relatively small diameter tool under the greatpressure induced by the falling mass of metal above it.

Having thus described my improved structure, what I claim is:

l. A blasting bomb adapted to be forced into the formation to be blastedcomprising an elongated cylinder containing an explosive, a hard pointon the lower end of the cylinder, a time fuse within the cylinder, afiring pin arranged to slide through the upper end of the cylinder 6 andnormally projecting therefrom, means operated by downward sliding of thepin for igniting the fuse, and a telescopic hood. over the upper end ofthe cylinder protecting said firing pin normally held in place bysecuring means displaceable by downward movement of said hood relativeto said cylinder.

2. A blasting bomb adapted to be forced into the formation to be blastedcomprising an elongated cylinder containing an explosive, a hard 15point on the lower end of the cylinder, a time fuse within the cylinder,9. firing device for said fuse arranged to operate through the upper endof saidcylinder by force applied from above, a tube within theexplosive-containing chamber 20 of the bomb holding an air supply forsaid fuse.

3. Blasting apparatus comprising a heavy metal shaft adapted to beraised and dropped, said shaft arranged to be suspended vertically fromthe upper end thereof, a cylinder contain- 26 ing an explosive disposedin substantially axial alignment with the shaft and projecting from itsopposite end, said bomb being releasably secured -to the shaft and meanspermitting axial movement of the shaft and cylinder relatively 30 uponthe cylinder being driven into the formation when the shaft is dropped,and delay firing means for setting off the explosive actuated by thesaid axial movement of the shaft and cylinder relatively.

4. Blasting apparatus comprising a. weight adapted to be raised anddropped, a bomb, means temporarily securing the bomb to the lower end ofsaid weight, said weight being appreciably heavier than the bomb fordriving the bomb into 40 the formation to be blasted upon dropping theweight, delay firing means for setting off the bomb operated upon thebomb striking the formation and giving time for removal of the weightbefore the bomb is exploded, said firing means including a time fusewithin the bomb, an ignition device at the end of the fuse, and acooperating ignition device adapted to be moved through relativemovement of the weight and bomb, and means for withdrawing the weightmfrom the bomb after the bomb has been driven into the formation and isheld thereby.

5. Blasting apparatus comprising a weight adapted to be raised anddropped, a bomb, means for temporarily securing the bomb to the lowerend of said weight, said weight being appreciably heavier than the bombfor driving the bomb into the formation to be blasted upon droppingthe.weight,1 delay firing means for setting off the bomb operated uponthe bomb striking go the formation and giving time for removal of theweight before the bomb is exploded, said firing means including a. timefuse within the bomb, an ignition device at the end of the fuse, and afiring pin adapted to be forced downward 35 by the weight and arrangedto actuate said ignition device, and means for withdrawing the weightfrom the bomb after the bomb has been driven into the formation and isheld thereby.

6. A blasting bomb adapted to be driven into 7 the formation to beblasted comprising an elongated cylinder provided with a hard drivingpoint atone end and containing an explosive,

a time fuse within the cylinder, a firing device for said fuse arrangedand adapted to be actuated w by application of a force external 02 thecylinder fuse within the cylinder, 8. device for said fuse arranged andadapted to be actuated by application of a force external 01 thecylinder and an air container within the explosive containing cylinderprovided with an opening communicating with said fuse for supplying airfor said fuse.

' FRAN KW. cm.

